Classifications

• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F1/00—Treatment of water, waste water, or sewage
  • C02F1/50—Treatment of water, waste water, or sewage by addition or application of a germicide or by oligodynamic treatment
• • A—HUMAN NECESSITIES
  • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
  • A01N—PRESERVATION OF BODIES OF HUMANS OR ANIMALS OR PLANTS OR PARTS THEREOF; BIOCIDES, e.g. AS DISINFECTANTS, AS PESTICIDES OR AS HERBICIDES; PEST REPELLANTS OR ATTRACTANTS; PLANT GROWTH REGULATORS
  • A01N35/00—Biocides, pest repellants or attractants, or plant growth regulators containing organic compounds containing a carbon atom having two bonds to hetero atoms with at the most one bond to halogen, e.g. aldehyde radical
  • A01N35/04—Biocides, pest repellants or attractants, or plant growth regulators containing organic compounds containing a carbon atom having two bonds to hetero atoms with at the most one bond to halogen, e.g. aldehyde radical containing aldehyde or keto groups, or thio analogues thereof, directly attached to an aromatic ring system, e.g. acetophenone; Derivatives thereof, e.g. acetals

Definitions

• Aqueous o-phthalaldehyde-(OPA)-glutaraldehyde solutions have hitherto been prepared by simply dissolving crystalline OPA in an aqueous glutaraldehyde solution, and are used, for example, for preparing biocides (U.S. Pat. No. 5,128,051).
• OPA exists in crystalline form and, in this form, has several disadvantages since it is poisonous and leads to skin irritation, making handling of OPA difficult. Furthermore, OPA tends, over prolonged storage periods, to block, as a result of which lengthy detachment processes are required which may possibly lead to discoloration of the OPA.
• the object of the present invention was therefore to find a preparation method for aqueous OPA-glutaraldehyde solutions which avoids direct handling of crystalline OPA and the disadvantages associated with OPA storage.
• this object can be achieved by a process in which the aqueous OPA-glutaraldehyde solution is obtained by cleavage of an OPA acetal in aqueous glutaraldehyde solution.
• the present invention accordingly provides a process for preparing an aqueous o-phthalaldehyde-glutaraldehyde solution which comprises converting an acetal of the o-phthalaldehyde in a 10 to 60% strength aqueous glutaraldehyde solution into o-phthalaldehyde at room temperature up to 100° C. by eliminating the corresponding alcohol, and removing the eliminated alcohol to give the aqueous o-phthalaldehyde-glutaraldehyde solution.
• the process according to the invention uses an OPA acetal as starting material.
• suitable acetals are dialkoxyphthalans or tetraalkyl acetals of OPA having, preferably, from 1 to 4 carbon atoms in the alkoxy moiety. Particular preference is given to using dialkoxyphthalans.
• Tetraalkyl acetals of OPA are described, for example, in U.S. Pat. No. 5,326,438.
• the corresponding dialkoxyphthalan can be obtained, for example, by a process which uses, for example, unpurified OPA as starting material.
• a solution of an OPA, obtained by any desired preparation process, in an alcohol having from 1 to 4 carbon atoms is firstly prepared.
• Alcohols having, preferably, from 1 to 4 carbon atoms are methanol, ethanol, propanol and butanol. Preference is given to methanol and ethanol, and particular preference to methanol.
• OPA can, for example, be prepared from dimethoxybenzene by an electrochemical route or by ozonolysis of naphthalene. Preference is given to an OPA prepared by ozonolysis, for example according to U.S. Pat. No. 4,769,464. If an OPA prepared by ozonolysis of naphthalene is used as starting material, it is already in the form of an alcoholic solution after ozonolysis, reduction of the peroxides and subsequent removal of the catalyst.
• this solution also contains naphthalene, phthalide, methoxyphthalan, and aldehydic acids and aldehydic esters, such as glyoxal, glycolates or glyoxylates, or fragments thereof or their sodium salts, the degree of impurity being between 5 and 90%, depending on the quality of the hydrogenation catalyst.
• the process is independent of the nature and the content of impurities.
• the alcoholic solution containing the unpurified OPA is then adjusted to a pH between 0 and 3, preferably between 0.5 and 2, by acidification.
• Suitable acidifiers are mineral acids, such as HCl, H 2 SO 4 , H 3 PO 4 , organic acids, such as formic acid, acetic acid, p-toluenesulfonic acid or methylsulfonic acid, or acidic ion exchangers. Preference is given to mineral acids, and particular preference to H 2 SO 4 .
• the temperature in this step is from 0° to 65° C., preferably from 15° to 30° C. Acidification converts the OPA to be purified into the corresponding dialkoxyphthalan.
• Any sodium sulfate precipitate that forms may be removed and the remaining solution of the phthalan formed is mixed with up to 50% strength aqueous alkali solution in the next step.
• suitable alkali solutions are sodium hydroxide solution or potassium hydroxide solution. Preference is given to sodium hydroxide solution.
• the alcohol used as solvent is subsequently or simultaneously distilled off.
• the chosen pressure and temperature depend on the alcohol used. Distilling off the alcohol leaves a salt solution containing the phthalan. If solid salts are present in this solution, it is diluted with water in. order to dissolve these salts.
• the corresponding dialkoxyphthalan is extracted from the organic phase using common extractants, such as, for example, ethers, for example diethyl ether, diisopropyl ether, methyl tert-butyl ether etc., or using ethyl acetate or toluene etc.
• common extractants such as, for example, ethers, for example diethyl ether, diisopropyl ether, methyl tert-butyl ether etc., or using ethyl acetate or toluene etc.
• Preferred extractants are methyl tert-butyl ether, ethyl acetate and toluene.
• the chosen temperature during the extraction process is dependent on the extractant used and is preferably between room temperature and 80° C.
• the resultant dialkoxyphthalan can be purified by distillation, after which it is in the form of a colorless liquid which can be stored indefinitely at room temperature.
• the amount of acetal used depends on the desired end concentration of OPA in the glutaraldehyde solution. Using the process according to the invention it is possible to obtain glutaraldehyde solutions having an OPA content of up to 30% by weight.
• the aqueous glutaraldehyde solution used is a 10 to 60% strength by weight solution, preferably a 30 to 55% strength by weight solution.
• An amount of acetal which corresponds to the desired end concentration of OPA is then mixed with the aqueous glutaraldehyde solution.
• the mixture is then further diluted with sufficient water for the concentration of the glutaraldehyde solution to remain constant during the subsequent distillation of the eliminated alcohol.
• the reaction temperature depends on the alkoxy radical in the acetal and is preferably between room temperature and 100° C.
• the reaction to give OPA can also be carried out at a pressure from normal pressure to a pressure of 300 mbar, preferably up to a pressure of 200 mbar, depending on the alkoxy radical.
• the alcohol which is eliminated is then distilled off under reduced pressure. Water may again be added to maintain a constant concentration.
• the resulting aqueous OPA-glutaraldehyde solution can be adjusted to an OPA content of from 1 to 30% by weight, preferably from 1 to 10% by weight, by further dilution with glutaraldehyde solution, and can be used directly, for example, for biocide preparation.
• the still temperature was 61.1° C., and 1315 g of solution having a pH of 3.47 remained in the still.
• the head temperature was 59.7° C. and 189 g of distillate were obtained.
• the end point of the reaction was determined using GC and complete cleavage was reached at a content of ⁇ 0.1 area % of acetal.
• 100 g of the still solution were mixed with 107. g of 50% strength aqueous glutaraldehyde solution to give an OPA content of approximately 3% by weight.
• Still temperature 60.1° C.-61.4° C.

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• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Plant Pathology (AREA)
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• Water Supply & Treatment (AREA)
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• Organic Chemistry (AREA)
• Agronomy & Crop Science (AREA)
• Hydrology & Water Resources (AREA)
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• 1996
  • 1996-11-26 AT AT0205396A patent/AT404592B/de not_active IP Right Cessation
• 1997
  • 1997-11-17 IN IN3284DE1997 patent/IN187090B/en unknown
  • 1997-11-18 AT AT97120163T patent/ATE223647T1/de not_active IP Right Cessation
  • 1997-11-18 DE DE59708182T patent/DE59708182D1/de not_active Expired - Fee Related
  • 1997-11-18 DK DK97120163T patent/DK0843966T3/da active
  • 1997-11-18 EP EP97120163A patent/EP0843966B1/de not_active Expired - Lifetime
  • 1997-11-18 ES ES97120163T patent/ES2180877T3/es not_active Expired - Lifetime
  • 1997-11-25 CN CN97126296A patent/CN1093850C/zh not_active Expired - Fee Related
  • 1997-11-25 JP JP32316997A patent/JP3968160B2/ja not_active Expired - Fee Related
  • 1997-11-26 US US08/979,952 patent/US5872153A/en not_active Expired - Fee Related

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